The ENVI-met Knowledge Base aims to explain some of the ENVI-met features and aspects about the simulation in deeper detail than the basic documentation does. It also is an essence of the different FAQ and disussions raised in the ENVI-met bulletin board over the time.
You can start browsing & reading here, but you will also find cross-links to the connected Knowledge Base items in the different topics concerned. Also, occasionally ENVI-met will suggest you to have a look at some of the items.